微创超声乳化手术前后角膜前后表面及不同区域范围角膜参数的变化

目的：比较白内障微创超声乳化手术前后角膜前表面屈光力(ASF)、角膜真实净屈光力(TNP)和总角膜屈光力(TCRP)分布特点及角膜前后表面曲率半径比(B/F ratio)差异。

方法：前瞻性研究。收集2020-12/2021-05就诊于潍坊眼科医院行2.2mm微切口超声乳化白内障吸除联合人工晶状体植入术的年龄相关性白内障患者156例156眼。术前及术后3mo行Pentacam眼前节生物测量仪检查，收集以角膜顶点和以瞳孔为中心2、4、6mm环上和区域内ASF、TNP和TCRP，以及手术前后B/F ratio。

结果：术后3mo，以角膜顶点为中心2mm直径环上和区域内ASF值较术前均无差异(均P>0.05)，而4、6mm直径环上和区域内ASF值较术前均有差异(均P<0.05)； 以瞳孔为中心2mm直径环上及区域内ASF值较术前均无差异(均P>0.05)。以角膜顶点为中心和以瞳孔为中心2、4、6mm直径环上和区域内TNP、TCRP值较术前均有差异(均P<0.05)。术前以角膜顶点为中心和瞳孔为中心在2mm与6mm之间环上和4mm与6mm之间环上TCRP值均有差异(均P<0.0167)； 在2mm与6mm区域内TCRP值均有差异(均P<0.0167)； 术后3mo，以角膜顶点为中心和瞳孔为中心环上TCRP值在2mm与6mm之间、4mm与6mm之间均有差异(均P<0.0167)，而以角膜顶点为中心和瞳孔为中心区域内TCRP值仅在2mm与6mm直径范围内有差异(P<0.0167)。B/F ratio术前为81.79%±1.87%，术后3mo为80.68%±2.23%(P<0.001)。

结论：白内障手术前后以角膜顶点和以瞳孔为中心的不同直径环上及区域内各项角膜屈光力参数会有一定的变化和差异，人工晶状体度数计算的K值选择及基于角膜特性的人工晶状体个体化选择时应予以考虑。     

飞秒激光辅助超声乳化联合Ahmed青光眼引流阀植入术治疗合并难治性青光眼的白内障

目的：评估飞秒激光辅助超声乳化联合Ahmed青光眼引流阀植入术治疗合并难治性青光眼的白内障的有效性和安全性。

方法：回顾性病例对照研究。2019-10/2021-10入院合并难治性青光眼的白内障患者53例53眼，依据自愿选择分为飞秒激光辅助白内障超声乳化(FLACS)组26例26眼和常规白内障超声乳化(CPCS)组27例27眼。两组分别行FLACS和CPCS联合Ahmed青光眼引流阀植入术。比较两组患者术中超声乳化能量释放量(CDE)、有效超声时间(EPT)的差异和术前与术后抗青光眼药物数量的变化，以及术后观察不同时期(1d，1wk，1、3mo)在提高最佳矫正视力(BCVA)，降低眼压、角膜内皮细胞损伤程度和手术并发症及成功率状况。

结果：FLACS组术中CDE和EPT明显低于CPCS组(t=8.50、5.16； P<0.01、=0.001)。两组术后抗青光眼药物较术前均明显减少(t=9.12、7.76； P=0.011、0.016)，但两组间无差异(t=1.79，P=0.082)。两组术后BCVA均较术前改善，眼压均较术前降低(P<0.05)。FLACS组在术后早期(1d，1wk)BCVA的改善较CPCS组更显著(t=9.74、8.49； P=0.008、0.012)，但在术后1、3mo的BCVA改善程度并无不同(t=0.62、0.44； P=1.415、2.021)。CPCS组在术后随访不同时期的角膜内皮细胞损伤较FLACS组更明显(P<0.05)。术后随访的不同时期FLACS组和CPCS组在控制眼压方面无差异(F_组间=0.64，P_组间=0.421)。FLACS组的手术并发症发生率27%(7/26)较CPCS组89%(24/27)低(χ²=20.95，P<0.01)，其中角膜水肿(8% vs 41%)、前囊撕裂(0 vs 11%)在FLACS组中明显低于CPCS组，后囊破裂(0 vs 7%)、玻璃体脱出(0 vs 4%)及人工晶状体偏位(0 vs 7%)也均发生在CPCS组。但两组的治疗总成功率相近(P=28.718)。

结论：飞秒激光辅助超声乳化联合Ahmed青光眼引流阀植入术可充分发挥联合手术的精准微创可控优势，帮助合并难治性青光眼的白内障患者有效降低眼压及更早获得视力恢复。     

A Review of Machine Learning Techniques for Keratoconus Detection and Refractive Surgery Screening

ABSTRACT

Various machine learning techniques have been developed for keratoconus detection and refractive surgery screening. These techniques utilize inputs from a range of corneal imaging devices and are built with automated decision trees, support vector machines, and various types of neural networks. In general, these techniques demonstrate very good differentiation of normal and keratoconic eyes, as well as good differentiation of normal and form fruste keratoconus. However, it is difficult to directly compare these studies, as keratoconus represents a wide spectrum of disease. More importantly, no public dataset exists for research purposes. Despite these challenges, machine learning in keratoconus detection and refractive surgery screening is a burgeoning field of study, with significant potential for continued advancement as imaging devices and techniques become more sophisticated.     

Clinical features and possible founder mutation of the 8bp duplication mutation in the SLC4A11 gene causing corneal dystrophy and perceptive deafness in three South American families

Background: Corneal Dystrophy and Perceptive Deafness (CDPD) or Harboyan syndrome is an autosomal recessive rare disorder, characterized by congenital corneal opacities and progressive sensorineural hearing loss, which usually begins after the second decades of life. This study reports the ophthalmic, audiological and genetic features, in five CDPD affected patients from three Chilean families.

Materials and Methods: Five individuals affected with CDPD from three unrelated Chilean families were clinically and genetically examined. To evaluate a putative founder mutation 7 SNPs were analyzed in the three families, an Argentinian patient (carrier of the same mutation previously reported) and 87 Chilean controls.

Results: The ophthalmic symptoms in the five patients were bilateral and symmetric, starting before one year of age, and visual acuity varied from 0.1 to 0.3. In all cases, hearing loss began over 8 years old. The sequence of the 19 exons of SLC4A11 gene of all the affected patients exhibited homozygous eight nucleotide sequence duplication (c.2233_2240dup TATGACAC, p.(Ile748Metfs*5)) at the end of exon 16. All the affected patients of the three families were homozygous for a haplotype composed of five SNPs and covering 4,1 Mb. The same haplotype was present in one allele of the heterozygous Argentinean patient and has a frequency of 2.76% in Chilean population.

Conclusions: The five CDPD patients were homozygous for the same mutation in the SLC4A11 gene. Haplotype analysis of all the affected, including the case reported from Argentina was in accordance with a founder mutation.     

Introduction and evaluation of a novel multi-camera surface topography system

BackgroundSurface topography can be used for the evaluation of spinal deformities without any radiation. However, so far this technique is limited to posterior trunk measurements due to the use of a single posterior camera.Research questionPurpose of this study was to introduce a new multi camera surface topography system and to test its reliability and validity.MethodsThe surface topograph uses a two-camera system for imaging and evaluating the subjects front and back simultaneously. Inter- and intra-rater reliability was tested on 40 human subjects by two observers. For validation human, subjects were scanned by MRI and surface-topography. For additional validation we used a phantom with an anthropomorphic body which was scanned by CT and surface topography.ResultsInter- (0.97−0.99) and intra-rater reliability (0.81−0.98) testing revealed good and excellent results in the detection of the body surface structures and measurement of areas and volumes. CT based validation revealed good correspondence between systems in the imaging and evaluation of the phantom model (0.61–10.52 %). Results on validation of human subjects revealed good to moderate results in the detection and measurements of almost all body surface structures (1.36–13.34 %). Only measurements using jugular notch as a reference showed moderate results in validity (0.62–27.5%) testing.SignificanceWe have introduced a novel and innovative surface topography system that allows for simultaneous anterior and posterior trunk measurements. The results of our reliability and validity tests are satisfactory. However, in particular around the jugular notch region further improvements in the surface topography reconstruction are needed.     

角膜内皮移植术后早期玻璃酸钠对泪膜及角膜上皮细胞再生的作用

目的　研究1 g·L^-1和3 g·L^-1玻璃酸钠（hyaluronate，HA）滴眼液对角膜内皮移植术后早期泪膜及角膜上皮细胞再生的作用。方法　选择2017年9月至2018年2月在北京大学第三医院行角膜内皮移植术的患者60例（60眼），随机分成1 g·L^-1HA组和3 g·L^-1HA组，每组各30例，观察标准干眼评估问卷（SPEED）评分、结膜角膜染色评分（OSS）、泪膜破裂时间（TBUT）、角膜上皮缺损范围，进行激光共聚焦显微镜检查。比较不同时间点组间、组内各指标差异。结果　SPEED评分:各时间点两组间比较差异均无统计学意义（均为P>0.05）。组内比较:两组组内术后7 d、14 d、28 d均低于前一时间点（均为P=0.000），余相邻时间点两两比较差异均无统计学意义（均为P>0.05）。TBUT:术后7 d、14 d、28 d 3 g·L^-1HA组均显著高于1 g·L^-1HA组（均为P<0.05），而术前组间差异不显著；组内比较:1 g·L^-1 HA组后一时间点较前一时间点、3 g·L^-1HA组术后7 d较术前均显著延长(均为P<0.05)，而3 g·L^-1HA组术后14 d、28 d与前一时间点差异均无统计学意义（均为P>0.05）。 OSS评分:术前及术后1 d、3 d两组间比较差异均无统计学意义（均为P>0.05），术后7 d、14 d、28 d 3 g·L^-1HA组均显著低于1 g·L^-1HA组（均为P<0.05）；组内比较:两组术后1 d OSS评分均显著高于术前（均为P=0.000），其余时间点两组均低于前一时间点（均为P=0.000）。角膜上皮缺损范围:术后1 d 两组间比较差异均无统计学意义（均为P>0.05），术后3 d、7 d 两组间比较，以及两组组内与前一时间点比较差异均有统计学意义（均为P<0.05）。角膜基底细胞密度:术前、术后28 d两组间比较，以及1 g·L^-1HA组组内术前与术后28 d比较差异均无统计学意义（均为P>0.05），而3 g·L^-1 HA组术后28 d显著低于术前（P=0.002）。结论　HA可以有效改善角膜内皮移植术后早期泪膜状态并促进角膜上皮细胞再生，存在浓度依赖性。